Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Date:   Thu, 22 Nov 2018 09:09:13 +0800
From:   Ming Lei <ming.lei@redhat.com>
To:     Christoph Hellwig <hch@lst.de>
Cc:     Jens Axboe <axboe@kernel.dk>, linux-block@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-mm@kvack.org,
        Theodore Ts'o <tytso@mit.edu>, Omar Sandoval <osandov@fb.com>,
        Sagi Grimberg <sagi@grimberg.me>,
        Dave Chinner <dchinner@redhat.com>,
        Kent Overstreet <kent.overstreet@gmail.com>,
        Mike Snitzer <snitzer@redhat.com>, dm-devel@redhat.com,
        Alexander Viro <viro@zeniv.linux.org.uk>,
        linux-fsdevel@vger.kernel.org, Shaohua Li <shli@kernel.org>,
        linux-raid@vger.kernel.org, David Sterba <dsterba@suse.com>,
        linux-btrfs@vger.kernel.org,
        "Darrick J . Wong" <darrick.wong@oracle.com>,
        linux-xfs@vger.kernel.org, Gao Xiang <gaoxiang25@huawei.com>,
        linux-ext4@vger.kernel.org, Coly Li <colyli@suse.de>,
        linux-bcache@vger.kernel.org, Boaz Harrosh <ooo@electrozaur.com>,
        Bob Peterson <rpeterso@redhat.com>, cluster-devel@redhat.com
Subject: Re: [PATCH V11 02/19] block: introduce multi-page bvec helpers
Message-ID: <20181122010912.GB20814@ming.t460p>
References: <20181121032327.8434-1-ming.lei@redhat.com>
 <20181121032327.8434-3-ming.lei@redhat.com>
 <20181121131928.GA1640@lst.de>
 <20181121150610.GA19111@ming.t460p>
 <20181121160811.GA4977@lst.de>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20181121160811.GA4977@lst.de>
User-Agent: Mutt/1.9.1 (2017-09-22)
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On Wed, Nov 21, 2018 at 05:08:11PM +0100, Christoph Hellwig wrote:
> On Wed, Nov 21, 2018 at 11:06:11PM +0800, Ming Lei wrote:
> > bvec_iter_* is used for single-page bvec in current linus tree, and there are
> > lots of users now:
> > 
> > [linux]$ git grep -n "bvec_iter_*" ./ | wc
> >     191     995   13242
> > 
> > If we have to switch it first, it can be a big change, just wondering if Jens
> > is happy with that?
> 
> Your above grep statement seems to catch every use of struct bvec_iter,
> due to the *.
> 
> Most uses of bvec_iter_ are either in the block headers, or are
> ceph wrappers that match the above and can easily be redefined.

OK, looks you are right, seems not so widely used:

$ git grep -n -w -E "bvec_iter_len|bvec_iter_bvec|bvec_iter_advance|bvec_iter_page|bvec_iter_offset" ./  | wc
     36     194    2907

I will switch to that given the effected driver are only dm, nvdimm and ceph.

Thanks,
Ming